In the formation of a semiconductor wafer, integrated circuit devices such as transistors are first formed at the surface of a semiconductor substrate. Interconnect structures are then formed over the semiconductor substrate and the integrated devices. Connectors are formed on the surface of the semiconductor wafer, so that the integrated circuit devices can be accessed. The semiconductor wafer is sawed into a plurality of semiconductor chips.
The packaging of the semiconductor chips may be performed through reflow processes, wherein solder regions between the connectors of the semiconductor chips are reflowed to bond the semiconductor chips to other package components such as device dies, interposer, package substrates, or the like. In the reflow processes, the solder regions are molten, and the shapes and the profiles of the molten solder region are difficult to control. This may cause problems such as bridging, and hence the deterioration of the bonding quality or the yield loss.